A clutch conventionally has a reaction plate, a movable pressure plate, and a friction disk mounted between said reaction and pressure plates. Movement of the pressure plate is controlled by a diaphragm, controlled in turn by a release bearing. The friction disk is rotationally connected to an input shaft of a gearbox, and the reaction plate is, for example, rotationally integral with a flywheel connected to the driving shaft, for example a crankshaft of an internal combustion engine.
The release bearing is controlled by an actuator driven by an electronic computer so as to exert a predetermined force on the diaphragm and displace it a given distance.
The pressure plate is thus movable between an engaged position in which the friction disk is clamped between said pressure and reaction plates, and a disengaged position in which the friction disk is released.
It is known to use a release bearing having a tubular body intended to be passed through by the input shaft of the gearbox, and an actuator having a tubular movable part, also called a “piston,” engaged into an annular pressure chamber of the body and movable in translation parallel to the axis of the body. The piston of the actuator is intended for actuation of a clutch diaphragm, for example by means of a ball bearing. The piston is thus movable between an engaged position in which an engine torque is transmitted to the input shaft of the gearbox, and a disengaged position in which no torque is transmitted to that shaft.
A release bearing of this kind thus has an actuator of the concentric slave cylinder (CSC) type.
A release bearing of this kind is known in particular from the document FR 2 786 837, in the name of the Applicant.
The tubular body of this release bearing has a fluid supply orifice opening into the pressure chamber and attached to a supply conduit.
The use of a conduit and of appropriate attachment means is a laborious solution, and requires complex assembly.